public class Test {
    public static void main(String[] args) {
        MySingleList mySingleList = new MySingleList();
        mySingleList.creatList();
        mySingleList.display();
        int ret = mySingleList.size();
        System.out.println(ret);
        System.out.println(mySingleList.contains(12));
        mySingleList.addFirst(666);
        mySingleList.display();
    }
}
